Differential manometer.



F. E. WOLF. DIFFERENTIAL MANOMETER. APPLIOATION FILED JULY 11, 1911.

1 974,306. 1 Patented Sept. 30, 1913.

" NITED STATES PATENT, oFEIo rRANz EIVIIL woLr, or NOWAWES, NEAE rorsDAM, GERMANY.

DIFFERENTIAL MANoM rEE.

To all whom it may concern:

-Be it known that-I, FRANZ EMIL WOLF, engineer, a subject of the King of Prussia, residing at Nowawes, near Potsdam, in the Kingdom of Prussia and Empire of Germany, have invented certain new and useful Improvements in Differential Manometers, of which the following is aspecification.

My invention relates to improvementsin differential manometers by means of which the difference of the pressure of two fluids or of the same fluid at di'iferent parts of a conduit-or the like.can directly be ascertained. And the object of the improvements is'to provide a differential manometer in which inaccuracies such as are caused by friction of the operative partsfand by untightness 1 of the pressure chambers are avoided. As is known in the art in manometers of this class the elastic member ordinarily in the form of a diaphragm which is 7 exposed to the pressures of both fluids must be connected with a suitable indicating device, and in manometers such as are now in use the connecting member is guided in'a stufiing box which causes friction whereby the regular displacement of the diaphragm is impaired, and the pressure within the pressure chambers is subjected to' changes by the escape of fluid through the stufling box.

My invention consists in rigidly and tightly securing the said connecting member to the wall of the casingqand toform the part of the wall to which the connecting member is secured of highly elastic -material, so that it follows the displacements of the connecting member without opposing any resistance thereto. And in the preferred form of the invention the part of the wall of the casing to which the connecting Y member is secured is constructed in the form of a very elastic tube which at an open end is tightly secured to the casing and'at its opposite closed end is secured to the connectmg member;

In order that my invention maymore;

clearly be understood two examples embodying the same have been shown in the accompanying drawing in which Figure 1, is a vertical cross-section of-the apparatusQand Fig. 2, is'a'vertical cross-section of a modification of the apparatus;

Referring to the example illustrated in Fig. 1, the apparatus consists'of a casing a 5 5 which by a diaphragm m is divided into ,two "chambers 1 and 2 respectwel 'y connected by i I v v Specification of Letters Patent. Patented Sept. 30, 1913. Application filed Ju1y 11, 1911. Serial N0- 637,860.

' conduits 3 and 4 with the fluids-of different pressures, or with different parts of a fluid chamber. To the diaphragm a rod 6' is secured by means of which the displacements of. the diaphragm are transmitted to a suit able indicating device which in the drawing has been represented by a hand 0. Tlies'aid rod extends through a tube d or pocket which with its o-penouter end is soldered'or otherwise secured to a stud e projecting I from the casing, and which is closed at its inner end. This pocket (l forms an elasticpart of the wall of the casing a and may indeed be regarded as a sort of second'diaphragm. The rod 6 extends through the closed inner end of the tube d and it is tightly secured thereto. The tube {(Z- is highly elastic so that it yields to any pres- ,sure. exerted thereon by the diaphragm through the rod 6. In the example'shown =-1n the drawing the said tube is made-elastic by having its wall provided with suitable depressions, and in the preferred form the tube is undulated. By reason of its connection with the elastic tube 03 through the, rod 6 the operative surface of the diaphragm is reduced by an amount which is equal to i the cross section of the rod. In order to avoid an error in the measurement, I prefer to provide a similar tube d arranged in chamber-2 symmetrically placed at the opposite side of the diaphragm and connected thereto b arod having the same cross-section as the rod- 6, so that the active surface of the diaphragm on the side of the chamber 2 is reduced by a corresponding amountr In the example shown in Fig. 2 the casing a is likewise provided with a diaphragm m, whereby the'casing is divided into two chambers 1 and 2 connected respectively with the fluid supplies through. the conduits 3- and 4:. As shown the elastic tube d and the. connecting rod 6' located therein are dis posed parallel to the plane of the dia- Near its outer end and within a stud e to which the tube d is soldered or otherwise secured the rod 6 is fulcrumed between a pair of edges 9. At its outer end the rod 6 is connected to a lever 70 formed at its upper end as a toothed rack adapted to. engage a pinion of the indicating mechanism. To permit the rod 6' t'o'freely rock about the fulcrum 9 it is provided with a suitable joint h which in the example shown is located at'a point phragm, and the'rod b is connected with jthediaphragm by'a block f.

near the block f. I Also in this case a sec- I claim herem as my invention:

1 A differential manometer comprising a casing-wall a part of which is readily yield? ing; a diaphragm. which is mounted within said casing-wall and which forms'therewitha pair of fluid-pressure chambers, saidwall being formed withopenings one in each of said chambers, for the fluid; a pressure indicator; and a connector which connects said diaphragm and indicator-and transmits the movements of the diaphra to the indicator and which is fastene through the yielding part of said wall.

2. difi'erential manometer comprising a casing-wall a part of which is in the form of an elastic mounted within said casing-wall and forms therewith a pair said wall belnfi'formed with openings one in each of sai chambers, for the fluid; a

pressure indicator and a connector which connects said diaphragm and indicator and transmits the movements of the diaphragm to and extends pocket; a diaphragm which isof fluid-pressure chambers,

to the indicator and which is'fastenedto the;

bottom of said elastic pocket and extends therethrough.

3. A difi'erential manometer comprising a casing-wall a part of which is in the form of an elastic pocket; a diaphragm which is mounted within said casing-wall and forms therewith a pair of fluid-pressure chambers,

in each of said chambers, for the fluid, a pressure indicator; a connector which connects said diaphragm and indicator and transmits the movements of the diaphragm to the indicator and whlch is fastened to the bottom of said 'elastic pocket and extends therethrough; anda second elastic pocket arranged s mmetrically with respect to the In testimony whereof I aflix.my signature in presence of'two witnesses.

FRANZ EMIL woLF.

Witnesses: I

, FRIDA KLA]BER,

PAULINE Kmnsnn. v

35 said wall being formed with openings one 

